Punch retainer assembly

ABSTRACT

A punch retainer has a bore formed completely therethrough including a first portion and a second portion of greater crosssectional dimension than the first portion, the second bore portion being threaded. A button head type punch includes a body received in the first bore portion and an enlarged head which is received in the second bore portion. Backup means in the form of a threaded plug is threaded within the second bore portion and engages the head of the punch to positively hold the punch in position and to prevent relative axial movement of the punch with respect to the retainer. A plurality of annular spacer members are positioned between the head of the punch and an annular shoulder formed in the punch retainer.

United States Patent [151 3,641,860

Whistler, Sr. et al. 5] Feb. 15, 1972 [54] PUNCH RETAINER ASSEMBLY 791,548 6/1905 [72] Inventors: Lawrence V. Whistler, Sr., 259 Doncaster Road; Lawrence V. Whistler, Jr., 251 3'l37l93 6/1964 Doncaster Road, both of Kenmore, N.Y.

14217 Primary Examiner-James M. Meister [22] Filed: Nov. 14, 1969 Attorney-Imirie, Smiley. Snydcrfi Butrum 21 Appl. No.: 876,914

A punch retainer has n bore formed completely Iherellu'ougli (g 152: ineludingnfirst portion and a second portion otgreiuur t'l'mm [58] d 527 619 sectional dimension than the first portion. the necoml bore portion being threaded. A button head type punch includes a 83/686; rig/89'; 151/70 7 body received in the first bore portion and an enlarged hCuLl which is received in the second bore portion. Backup means in [56] References Cited the form of a threaded plug is threaded within the second bore UNITED STATES PATENTS portion and engages the head of the punch to positively hold the punch in position and to prevent relative axial movement 2,580,366 12/1951 Smith ..83/698 X f the punch with respect to the remineh A plurality f ahhu 3,149,524 9/1964 Vecchi ..83/70O X Spacer members are positioned between the head f the 1,958,941 5/ 1934 P "279/89 punch and an annular shoulder formed in the punch retainer. 3,379,083 4/1968 Burns et al. ..83/700 X 2,852,056 9/1958 Rapata ..1 51/7 9 Claims, 12 Drawing Figures PATENTEQFEB I 5 I972 3,641,860

SHEET 1 UF 2 ti 5' 86 52-1-1 6 I I E I I I I I 4 I 1/ II 32 I 62 I 62 28 I I 62 I I 28 I40 64 Fl G .8.

LAWRENCE v. WHISTLERS: a LAWRENCE v. WHISTLE R,Jr

ATTORNEYS PUNCH RETAINER ASSEMBLY BACKGROUND OF THE INVENTION The present invention relates to a punch retainer assembly, and more particularly to a punch retainer and button-headtype punch, wherein the nose of the punch may either be of circular cross-sectional configuration or of odd-shaped configuration such as square, rectangular and the like.

Punches become dull in use and periodically require resharpening. A particular objective of the present invention is to provide a construction wherein the punch may be resharpened from time to time and further wherein means is provided to enable the nose of the punch to remain in its original position relative to the punch retainer whereby the operating portion of the punch extending from the punch retainer will remain of constant length throughout extended use of the punch.

In a construction as shown in US. Pat. No. 3,137,193, it is necessary to provide an allowance for the obliquely extending setscrew which throws the punch slightly out of alignment with the base of the punch retainer. In some cases, a ball lock is provided in place of the setscrew shown in the aforementioned patent. It is a further important feature of the present invention to eliminate such a setscrew or spring pressed ball and to increase the accuracy and the concentricity between the punch and the bore within the punch retainer.

SUMMARY OF THE INVENTION A punch retainer has a bore formed completely therethrough including a first portion and a second portion of greater cross-sectional dimension and which is threaded. A button-head-type punch includes a body received in said first bore portion and an enlarged head is formed at one end thereof, the punch head being received in said second bore portion.

Backup means in the form of a threaded member is threaded into the second bore portion and engages the head of the punch for positively holding the punch in position and preventing relative axial movement between the punch and the punch retainer.

Means is provided for holding the backup member in operative position. Spacer means in the form of a plurality of annular members are disposed between the enlarged head of the punch and a shoulder formed in the punch retainer. At least one of these annular members is of different thickness from he remaining annular members, and the annular members can be selectively removed so as to enable the punch to be resharpened and then reinserted in position in the punch retainer with a suitable number of spacer members removed from the assembly so that the operating length of the punch extending outwardly of the punch retainer remains constant throughout use of the apparatus.

This construction enables the punch to be resharpened many different times and brought up to its original length outwardly of the associated punch retainer simply by adjusting the total thickness of the spacer means disposed between the head of the punch and the shoulder formed on the punch retainer.

Since the punch retainer has a bore formed completely therethrough, the construction of the present invention allows internal grinding and enhances the accuracy and concentricity between the punch and the bore of the punch retainer which can be held to a much closer tolerance than with prior art constructions.

With an arrangement as shown in the aforementioned patent, grinding must be carried out in a blind hole, whereas the present invention allows straight through grinding and much more accurate final alignment.

The present invention also eliminates the necessity of providing an obliquely extending setscrew or spring pressed ball for holding the punch in operative position with respect to the punch retainer.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a view partly broken away and partly in section illustrating one form of the present invention;

FIG. 1A is an exploded view in longitudinal section of the components shown in FIG. 1;

FIG. 2 is an exploded view partly in section illustrating a modified form of the invention;

FIG. 3 illustrates a portion of the threaded bore formed within the punch retainer shown in FIG. IA;

FIG. 4 is a view similar to FIG. 3 illustrating a further modified form of the invention;

FIG. 5 is a vertical section through a further form of the invention;

FIG. 6 illustrates a portion of the punch shown in FIG. 5;

FIG. 7 is a top view ofa pin employed in the form of the invention shown in FIG. 5;

FIG. 8 is an elevation of the pin shown in FIG. 7;

FIG. 9 is a longitudinal section through still another form of the invention;

FIG. 10 is a top view ofa further form of the invention; and

FIG. 11 is a longitudinal section through the construction shown in FIG. 10.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings wherein like reference characters designate corresponding parts throughout the several views, there is shown in FIG. 1 a punch shoe indicated generally by reference numeral 20 including a lower surface 22. A punch template 24 is disposed in spaced parallel relationship to the lower surface 22 of the punch shoe 20, the punch template being supported in operative position by suitable template support means of conventional construction.

A punch retainer is indicated generally by reference numeral 26, and a button-head-type punch supported thereby is indicated by reference numeral 28. As seen most clearly in FIG. 1A, punch retainer 26 is a magnetic-type punch retainer of the general type shown in the aforementioned patent. This punch retainer comprises a body portion 30 having a substantially collar 32 of reduced diameter formed at one end thereof and snugly received in a cooperating opening in the punch template to properly position the punch retainer.

The punch retainer has a bore fonned completely therethrough including a first cylindrical bore portion 34 and a second threaded bore portion 36 of enlarged cross-sectional dimension. An annular shoulder 38 is defined on the punch retainer between the two bore portions.

An inner nonmagnetic sleeve 40 is mounted on the inner portion of a groove formed in the upper outer portion of body means 30. Sleeve 40 is formed of a suitable nonmagnetic substance such as brass, aluminum or similar material, whereas body means 30 of the punch retainer is formed of a magnetic conductor such as an alloy steel or the like, or of a material that can be hardened throughout the entire body and still have a great amount of impact strength to withstand the constant pounding encountered in use. The upper end 42 of the inner sleeve is spun or flanged over for a purpose hereinafter described.

A permanent magnet 44 of substantially annular configuration is disposed in surrounding relationship to inner sleeve 40. The magnet may be of a relatively powerful permanent magnet type such as a magnet identified as Alnico No. 5. This magnet may also be formed of ceramic or other magnetic material if so desired.

An outer shielding sleeve 46 of nonmagnetic material such as brass is disposed in surrounding relationship to magnet 44 and is substantially flush with the outer surface body portion 30. The magnet is retained in operative position between sleeves 40 and 46.

A core member 50 formed of a suitable magnetically conductive substance such as cold rolled steel is of substantially annular configuration and is disposed between sleeves 40 and 46 and abuts the upper end of magnet 44. Core member 50 is provided with a circumferentially extending groove formed on the upper inner surface thereof which receives the turned over end 42 of inner sleeve 40 whereby the core member is retained in the operative position illustrated. This construction provides a strong magnetic field which firmly magnetically adheres the punch retainer to the lower surface of the associated punch shoe.

Punch 28 is of the button-head type and includes a punch body comprising nose 60, a first cylindrical portion 62 and a second cylindrical portion 64 of slightly larger cross-sectional dimension, an enlarged generally cylindrical head 66 being provided at the opposite end of the punch. The second cylindrical portion of larger cross-sectional dimension is provided so that a flat can be ground thereon as discussed in connection with FIGS. and 6 so as to accurately locate an odd-shaped punch having a punch point of noncylindrical cross section. If the punch body were of constant diameter throughout the length thereof, it would be necessary to grind a flat the full length of the punch body when the punch point is other than of circular cross section.

When the punch is inserted into the punch retainer, 3 plurality of spacer members are adapted to be positioned between the head of the punch and annular shoulder 38 formed in the punch retainer. These spacer members include a plurality of annular members 70 and 72. Three members 70 are illustrated, these members being of a predetermined thickness. A single annular member 72 is illustrated which is of a thickness substantially half that of each of members 70. It is evident that the arrangement shown enables a punch to be resharpened many times, the punch being shortened each time substantially the thickness of spacer member 72.

After the first sharpening, spacer member 72 is removed, and the apparatus is reassembled whereupon the length of the working end of the punch extending outwardly of the punch retainer will be the same as it was prior to the sharpening. After a second sharpening, one of spacer members 70 is removed and is replaced by spacer member 72. In this manner, the punch can be resharpened may different times and brought up to its original working length extending outwardly of the punch retainer by suitably varying the spacer members disposed between the head of the punch and the annular shoulder in the punch retainer. It is apparent that any suitable number and thickness of spacer members may be employed as required.

A backup means indicated generally by reference numeral 80 comprises a substantially cylindrical plug having threads 82 formed on the outer surface thereof which enables the backup member to be threaded within the threaded bore portion 36 of the punch retainer. When the punch is properly positioned within the punch retainer, backup means 80 is threaded downwardly until it is in contact with the head of the punch to positively retain the punch in operative position and to prevent relative axial movement between the punch and the punch retainer.

Backup member 80 is provided with a polygonal socket 84 in the upper surface thereof for receiving a suitable wrench for moving the backup member into and out of operative position. The backup member is also provided with a Nylok insert 86in the thread thereof to prevent the backup member from moving after being set tightly against the head of the punch.

Referring now to FIG. 2, a modified form of the invention is illustrated wherein the backup means includes a pair of similar cylindrical members 90 having threads 92 formed on the outer surface thereof to enable the backup members to be threaded into the threaded bore portion 36 of the punch retainer. Each of backup members 90 is provided with a polygonal socket 94 for receiving a suitable wrench. It is apparent that two threaded members 90 can be threaded into engagement with one another and with the head of the punch to securely lock members 90 in operative position and to positively hold the punch in position.

FIG. 3 is an enlarged view of threaded bore portion 36 of the punch retainer wherein a standard thread 100 is provided.

FIG. 4 illustrates a modified arrangement wherein a buttress thread 102 is provided. It is apparent that the backup means is provided with a thread corresponding to that provided in the bore of the punch retainer.

Referring now to FIGS. 5-8 inclusive, a further form of the invention is illustrated. This embodiment also comprises a magnetic-type punch retainer wherein the construction is similar in many respects to the punch retainer previously described, similar parts having been given the same reference numerals primed. The punch is also similar to that previously described and likewise has been given the same reference numerals primed. The only difference in the punch in this form of the invention as seen in FIG. 6 is the provision of a flat formed on the portion 64' of the punch.

Referring to FIG. 5, body means 30' includes a laterally extending extension 114 having an opening 116 formed therethrough and disposed parallel with the longitudinal axis of the bore formed through the punch retainer. A locating means in the form of a plug member 120 includes an enlarged head portion 122, the outer diameter of which is ground to fit snugly within an opening in an associated template so as to properly align the punch retainer. Plug 120 is somewhat smaller than collar 32 so that the punch retainer can only be inserted in the template in its proper position.

Plug 120 includes a reduced cylindrical portion 124 which fits snugly within opening 116. A threaded bore 126 extends longitudinally through plug 120. A washer 128 engages the upper surface of extension 114 and has a central opening formed therein which receives the threaded shank of a bolt 130 having an enlarged head formed thereon. The threaded shank of the bolt is threaded into bore 126 of the plug so as to retain the plug in operative position.

The means for positively and accurately positioning a punch within the punch retainer is similar to that shown in the aforementioned U.S. patent and as seen in FIG. 7 and 8 includes a pin having a flat 142 formed along one side thereof, it being noted that this flat extends from a first end portion 144 of the pin and tapers to the opposite end portion 146 of the pin. This flat forms an acute angle with respect to a plane extending parallel with the longitudinal axis of the pin and intersecting the outer periphery of the pin.

A transversely extending opening 150 is provided through body means 30 of the punch retainer, this opening snugly receiving pin 140. The longitudinal axis of opening 150 is disposed at an acute angle to a plane passing through the longitudinal axis of the bore formed through the punch retainer. This acute angle is substantially identical to the acute angle as discussed in connection with FIGS. 7 and 8 so that when pin 140 is fixed in operative position, flat 142 lies in a plane which extends substantially parallel to a plane passing through the longitudinal axis of the bore formed through the punch retainer. Flat 110 formed on punch 28' is adapted to abut snugly against the flat 142 formed on pin 140 to thereby accurately locate the punch in operative position.

Referring now to FIG. 9, a further modified form of the invention is illustrated, comprising a punch retainer having a bore formed completely therethrough including a first bore portion 162 and a second bore portion 164 which is of greater cross-sectional dimension and which is threaded.

The punch retainer includes a lateral extension 166 having an elongated slot 168 formed therethrough. Suitable bolts 170 extend through slot 168 for securing the punch retainer to a punch shoe provided with slots which receive the upper ends of the bolts. This is a well-known construction'for permitting selective adjustment of the punch retainer on a punch shoe.

A button-head-type punch is indicated generally by reference numeral 17l] and includes a punch body 172 having an enlarged head 174 formed at the upper end thereof. Spacer means indicated by reference numeral 176 is provided in the form of a plurality of annular spacer members similar to those previously described. A substantially cylindrical threaded backup member 180 similar to member 80 is threaded within bore portion 164 and engages the head of the punch for positively retaining the punch in operative position.

Referring now to FIGS. and 11, a further modification of the invention is illustrated wherein the components thereof are in many respects similar to those discussed in connection with FIG. 9, and similar parts have been given the same reference numerals primed.

The difference in the structure shown in FIGS. 10 and 11 from that shown in FIG. 9 is the fact that punch 170 is provided with a flat 170 on an upper enlarged part thereof, this flat cooperating with a complementary flat formed on a pin 192 which in all respects is identical with pin 140 previously described for positively positioning the punch in operative position.

As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is therefore illustrative and not restrictive.

We claim:

1. A punch retainer assembly comprising a punch retainer having a bore formed completely therethrough, said bore including a first portion and a second portion of greater crosssectional dimension than said first portion and an annular shoulder between said first and second bore portions, a button-headtype punch including a body, said punch having an enlarged head at one end thereof, the body of said punch being snugly received in said first bore portion and the enlarged head of the punch being received in said second bore portion and presenting an annular face in opposition to said annular shoulder, backup means received in said second portion for selected axial disposition therewithin means for holding said backup means in operative position, and spacer means between the head of said punch and said annular shoulder for selectively spacing said annular face of the head of the punch from said shoulder, said backup means being operatively associated with said punch for positively holding the punch in position sandwiching said spacer means between said annular shoulder and said annular face and preventing relative axial movement between the punch and the punch retainer.

2. Apparatus as defined in claim I, wherein said backup means is in contact with the head of said punch.

3. Apparatus as defined in claim 2, wherein said second bore portion is threaded said backup means comprising a threaded member threaded within the second bore portion.

4. Apparatus as defined in claim 1, wherein said spacer means comprises a plurality of separate annular members.

5. Apparatus as defined in claim 4, wherein at least one of said annular members is of a different thickness than another ofsaid members.

6. Apparatus as defined in claim 1, wherein the means for holding said backup means in operative position comprises a Nylok insert mounted on said backup means.

7. Apparatus as defined in claim 1, wherein said backup means comprises a plurality of separate members, each of said members being threaded, said second bore portion being threaded, said backup members being threaded into said second bore portion and being in contact with one another for holding the threaded members in operative position.

8. Apparatus as defined in claim I, wherein said punch retainer includes an extension extending laterally therefrom and including locating means for accurately positioning said punch retainer.

9. Apparatus as defined in claim 1, wherein said punch has a fiat formed thereon, said retainer having a transversely extending opening formed therein, a pin disposed within said opening in predetermined position therewithin, said pin having a flat formed thereon engaging the flat on said punch for accurately positioning the punch within the punch retainer. 

1. A punch retainer assembly comprising a punch retainer having a bore formed completely therethrough, said bore including a first portion and a second portion of greater cross-sectional dimension than said first portion and an annular shoulder between said first and second bore portions, a button-head-type punch including a body, said punch having an enlarged head at one end thereof, the body of said punch being snugly received in said first bore portion and the enlarged head of the punch being received in said second bore portion and presenting an annular face in opposition to said annular shoulder, backup means received in said second portion for selected axial disposition therewithin means for holding said backup means in operative position, and spacer means between the head of said punch and said annular shoulder for selectively spacing said annular face of the head of the punch from said shoulder, said backup means being operatively associated with said punch for positively holding the punch in position sandwiching said spacer means between said annular shoulder and said annular face and preventing relative axial movement between the punch and the punch retainer.
 2. Apparatus as defined in claim 1, wherein said backup means is in contact with the head of said punch.
 3. Apparatus as defined in claim 2, wherein said second bore portion is threaded said backup means comprising a threaded member threaded within the second bore portion.
 4. Apparatus as defined in claim 1, wherein said spacer means comprises a plurality of separate annular members.
 5. Apparatus as defined in claim 4, wherein at least one of said annular members is of a different thickness than another of said members.
 6. Apparatus as defined in claim 1, wherein the means for holding said backup means in operative position comprises a Nylok insert mounted on said backup means.
 7. Apparatus as defined in claim 1, wherein said backup means comprises a plurality of separate members, each of said members being threaded, said second bore portion being threaded, said backup members being threaded into said second bore portion and being in contact with one another for holding the threaded members in operative position.
 8. Apparatus as defined in claim 1, wherein said punch retainer includes an extension extending laterally therefrom and including locating means for accurately positioning said punch retainer.
 9. Apparatus as defined in claim 1, wherein said punch has a flat formed thereon, said retainer having a transversely extending opening formed therein, a pin disposed within said opening in predetermined position therewithin, said pin having a flat formed thereon engaging the flat on said punch for accurately positioning the punch within the punch retainer. 